1. Field of the Invention
The present invention relates to a fluorocarbon refrigerant used as a working fluid medium in a refrigerator and other refrigeration cycles. More particularly, the present invention relates to a so-called "Freon (Fron) substitute" containing no chlorine or bromine. The Freon substitute disclosed herein is a mixed refrigerant of fluorocarbons which is able to obtain a refrigeration temperature of -30.degree. C. or less.
2. Discussion of Background Information
Chlorofluorocarbons (CFC) have been widely used as the working fluid medium in various refrigeration cycles such as, for example, a refrigerator. However, it was recently found that CFC can damage the ozone layer of the earth. Also, to preserve the environment of the earth, each country has established its own regulations and schedules of regulations to inhibit and/or control the use of specified Freons including CFC in accordance with the provisions of international conventions. In addition to the control of specified Freons, research and development for providing a Freon substitute which does not contain chlorine, i.e., the detrimental substance which causes ozone layer damage, are being carried out in a great many companies and institutes. Moreover, as a result of recent studies, the ozone layer damage caused by the specified Freons was noted to be a very important and severe problem which must be promptly solved, and accordingly each country started to practice the established regulations earlier than scheduled.
On the other hand, Freon 502 (azeotropic mixture of HClF.sub.2 and C.sub.2 ClF.sub.5) and Freon 13B1 (CBrF.sub.3) are known to obtain a refrigeration temperature of -30.degree. C. or less. However, both of these Freons cannot be used or are listed high on the schedule of regulations, because they contain chlorine or bromine. A Freon substitute (HFC) having an evaporation temperature (boiling point) of -30.degree. C. or less has not yet been developed.